Steam syphon oil burner



Jan. 11, 1966 s. c. PATERSON STEAM SYPHON OIL BURNER Filed May 13, 1963 INVENTOR.

STANLEY C. PATERSON ATTORNEYS W M W United States Patent Ofllice 3 ,228,449 Patented Jan. 11, 1966 3,228,449 STEAM SYPHON OIL BURNER Stanley C. Paterson, Nahant, Mass. Waltham Heating Products, Inc., 1214 Bennington St, East Boston 28, Mass.)

Filed May 13, 1963, Ser. No. 279,901 6 Claims. (Cl. 15875) This invention relates generally to oil burning devices and more particularly to oil burning devices wherein a quantity of a fluid other than fuel oil is mixed with the oil prior to ignition.

Fuel oil of various grades is utilized in variou devices to provide a useful source of heat. The present invention is principally concerned with oil burning devices of the general size usually utilized in residential heating installations. Residential oil burners are generally designed to burn a more highly refined and less viscous fuel oil than are larger commercial and heavy industrial oil burners. While the subject matter of the present invention may be utilized with industrial and the like installations, it is particularly useful for residential heating purposes.

The most popular type of residential oil burner is known as the high-pressure atomizing burner. In this burner fuel oil is ejected from a suitable nozzle at high pressure and is properly atomized for ignition. This type of burner has, however, substantial limitations. In order to properly atomize the oil for burning, substantial quantities of oil are consumed at high pressure producing a substantial heat output. These burners cannot be successfully operated at heat outputs of less than 100,000 B.t.u. per hour.

These deficiencies can be overcome by a second type of oil burner known as the air atomizing burner. In this system compressed air is mixed with the fuel oil in an atomizing nozzle with the result that less fuel oil is needed to successfully produce a properly atomized nozzle discharge. The resulting flame is less intense with a correspondingly lower heat output. This system is generally successful in producing a lower heat output oil burner but is substantially more expensive and more complex through the requirement for an air compressing system in combination with the usual oil burner structure.

A further modification of the air atomizing oil burner could result in some simplification of the required structure. It would be possible, for example, to employ an oil nozzle which utilizes expanding compressed air to syphon the oil into the nozzle thereby eliminating the oil pump. It will be noted, however, that all the conventional elements of an oil burner would be still required due to the necessity for providing an air pump or compressor, motor, fan, etc. While an oil burner constructed according to these teachings would perform satisfactorily with respect to heat output minimum limits, there would still be no cost improvement over the conventional high pressure atomizing burner.

It is, accordingly, an object of the present invention to provide an oil burner having a minimum of operative elements and eliminating any necessity for a motor, fan, or pump.

It is a further object of this invention to provide an oil burner in which a fluid other than oil is added to the fuel oil prior to ignition thus producing a burner with substantially lower practical heat output minimum levels.

In the practice of the invention, in a preferred embodiment thereof, I provide a steam syphon oil burner in which a regulated, constant level boiler is employed to provide steam which mixes with the fuel oil in a syphoning atomizing nozzle. The resultant discharge is ignited in the usual fashion and a flame is produced having satisfactory combustion characteristics with a heat output substantially less than that of the high pressure atomizing burner.

It is a feature of the invention that the steam boiler employed is constructed such that only surface boiling occurs therein with substantial improvement in steam output.

It is a further feature of the invention that means are provided for periodically flushing the boiler thereof to purge it of unwanted sediment.

These and other objects and features of the invention will appear as the description proceeds with the aid of the accompanying drawings which illustrates a preferred embodiment of the invention in cross-sectional side view.

The single figure of the drawing shows a preferred embodiment of a steam syphon oil burner indicated generally at 10. A constant level boiler is provided having a bottom portion 12 and top portion 14. A sealing gasket 16 is interposed between the bottom 12 and the top 14 to provide a pressure tight boiler. The top 14 may be secured to the bottom 12 by any suitable means, as for example by bolts 18.

The boiler is divided into two interior chambers by a transverse baffle member 20 which extends entirely across the boiler. It will be noted that the baflle 20 is spaced from both the bottom 12 and top 14 of the boiler. The baflle 20 is thusly spaced to provide a pressure equilibrium within the boiler so that it may operate by gravity feed. An end wall 22 of the bottom 12 is fitted with an inlet water valve bushing 24 which extend therethrough for connection with a water supply line 26. The water supply line may be connected to the conventional residential water supply system (not shown) at static street pressure. The valve bushing 24 defines a valve seat 28 at its terminal portion inside the boiler. A float controlled valve member 30 i provided within the boiler and is operable against the valve seat 28. The float controlled valve member 30 may be of any suitable construction and in the preferred embodiment a bell crank 32 pivotally supported on the bottom 12 by a support 34 carries a needle valve 36 at one end and a suitable float 38 at the other end thereof. Lowering of the water level within the boiler from the condition illustrated in FIG. 1 causes the float 38 to move downwardly, thusly withdrawing the needle valve 36 from the seat 28 and permitting the entrance of supply water.

By means of the float controlled valve 30, the boiler may be maintained with a constant level of water 40. Since the baflle 20 is spaced from both the bottom 12 and top 14 of the boiler, the pressure at both sides of the baffle 29 will be substantially equal at all times regardless of the steam pressure which may be built up within the boiler.

Positioned at the opposite side of the baflie 20- from the float controlled valve 30 is an electrically operated heating element indicated generally at 42. In the illustrated embodiment the element 42 comprises a coiled immersion heating element 44 mounted between a pair of electrical terminals 46 which extend through the top 14 of the boiler. The terminals 46 are electrically insulated from the top 14 by insulating sleeves 48. Electrical connection to the terminals 46 is provided at an exterior lug 50 on each terminal 46. The illustrated immersion heating element is operable on conventional residential electrical supply sources, for example volts A.C. Leads indicated generally at 52 may connect the terminal lugs 50 to the source of current (not shown).

It will be observed that the heating element 44 of the preferred embodiment is initially positioned slightly below the surface of the water in the boiler. Since a constant Water level is maintained by the float controlled valve, accurate positioning of the heating element is possible. By positioning the heating element just beneath the surface of the water it will be noted that during operation of the element, boiling of the water will occur close to the surface thereof. By means of this construction, violent boiling of the water does not occur. Violent boiling of the water might result in the passage of water through the steam delivery system hereinafter to be described. Since it is desired to provide a steam output which contains no entrained water, it is imperative that the boiling action in the boiler be confined to the general surface portion of the water therein.

The baffle 20, in the absence of violent boiling as above described, serves as well to interrupt surface turbulence in the boiler which might otherwise act to operate the float controlled valve 30 and admit cold supply water to the boiler in an erratic, undesirable fashion.

It will also be noted that alternative forms of heating elements may be employed. For example, a pair of electrodes may be connected to the terminals 46 to extend a short distance below the surface of the water. Heating of the water by resistance of the current flow therethrough would produce an equally satisfactory steam output. An additional advantage of this latter structure would be its fail-safe characteristic wherein electric current would cease to flow should the water level drop below the electrodes. With this alternative structure it is still imperative, however, that the heating of the water be confined to its upper portion, slightly below the surface, in order to avoid violent boiling. Because of the lower density of hot water over cold water, the boiling action may be maintained in the general surface area, as noted, thus providing less violent boiling action and preventing water from being entrained in the steam. This construction additionally generates the maximum steam output for the lowest energy requirements.

The steam exits from the boiler through a passage 54 in the top 14 thereof. The steam then passes through a discharge pipe 56 to a steam atomizing nozzle 58. The steam atomizing nozzle 58 is so designed as to syphon oil into the nozzle through an oil line 60. The oil line 60 is in communication with a reservoir (not shown) containing the fuel oil to be burned. The reservoir may be placed below the boiler and it will be noted that the fuel oil will be syphoned from the reservoir by the action of the steam passing through the atomizing nozzle 58 thereby eliminating the conventional oil pump and motor.

The steam atomizing nozzle 58 is of conventional construction having a constricted terminal portion 62 and a fuel oil dispensing orifice 64 positioned within the bore of the nozzle 58 slightly behind the constricted terminal portion 62 thereof.

The atomizing nozzle 58 is mounted on a suitable frame member 66 which is rigidly secured to a wall 68 of a furnace 70 which it is desired to fire. The steam atomizing nozzle 58 extends through the wall 68 of the furnace. Ports 72 are provided in the frame 66 to admit combustion air to the furnace radially about the steam atomizing nozzle. In the operation of the invention it has been found that natural chimney draft is usually sufiicient to introduce sufficient combustion air for proper operation of the burner. As a result, no fans are required as in the conventional construction.

Ignition of the atomized oil spray is accomplished by conventional spark electrodes indicated generally at 74 positioned with-in the furnace 70 in the spray dispersion path. The electrodes 74 are mounted through the frame 66 by insulating members 76 and are connected at external terminals 78 to a conventional high voltage ignition source (not shown).

FIG. 1 also shows structure indicated generally at 80 for draining the boiler as may be required to purge it of sediment which may be produced by the boiling action. In the preferred embodiment a discharge pipe 82 is fitted to the bottom 12 of the boiler and communicates with the interior thereof. A drain valve 84 is positioned in the pipe 82 to permit the discharge of Water and sediment from the boiler. The drain valve illustrated is operated by a solenoid 86 of conventional design. A solenoid control circuit indicated generally at 88 is employed to open the sediment drain valve at predetermined intervals. It has been found that it is not necessary to drain the entire boiler to effect purging thereof but rather that draining of a portion of the contents at regular intervals will result in sufficient cleaning action. It will be noted that when the boiler is purged by the opening of the valve 84 the float controlled valve 30 is opened to admit sufiicient water to the boiler to maintain its operating level.

In the preferred embodiment a conventional pressure relief valve indicated generally at 90 is also provided. The pressure relief valve 90 is fitted through the top 14 of the boiler and may be set to vent the boiler if excessive steam pressure should occur. It will be noted that no other safety devices are required in connection with the present invention. If for any reason the boiler ceases to produce sufficient steam to operate the atomizing nozzle the syphoning of oil ceases and the flame is extinguished. It is likewise unnecessary to provide an oil pump to initiate the syphoning cycle since the syphon will start automatically when sufficient steam passes through the atomizing nozzle.

It will be noted that the operation of the boiler may be conveniently controlled by a conventional thermostat (not shown) which actuates the electrical supply to the heating element and initiates the operating cycle. The thermostat may also be provided with a conventional flame monitor and controls such as a thermal timer to activate the solenoid controlled drain valve 88 to initiate the boiler flushing cycle.

Many modifications and changes in the construction of the invention will be apparent to one skilled in the art to which it pertains. For example, the heating element may be of the alternative water resistance type as above described. Additionally, in cases where chimney draft is insufficient, a fan and motor may be added. In general, any conventional means of introducing combustion air may be employed and any conventional oil ignition system may be substituted for the spark electrodes illustrated. Further, reference herein to use of the invention with a furnace is not intended as a limitation but rather includes any heater, fire box or fire pit, it being obvious that the subject matter of the invention may be utilized in many different applications.

Having now described and illustrated a preferred embodiment of the invention what I claim as new and desire to secure by Letters Patent of the United States is:

1. An oil burner comprising a steam boiler, said steam boiler including a first compartment and a second compartment, means connecting an external supply of water to said first compartment of said steam boiler, float controlled valve means positioned within said first compartment and operable to maintain a constant level of water in said boiler, a wall within said boiler separating said first and said second compartments said wall extending less than the full distance to the top of said boiler and less than the full distance to the bottom of said boiler and extending higher than said constant water level therein to provide pressure equalization between said first and said second compartments and gravity flow of water from said first compartment to said second compartment, said wall isolating the valve means from the boiling action occurring in the second compartment, a heating element positioned in said second compartment immediately below the surface of said water whereby steam is produced in said boiler by surface boiling of the water therein, a steam outlet from said boiler, .an atomizing nozzle, means connecting said steam outlet to said atomizing nozzle, a supply of fuel oil, means connecting said supply of fuel oil to said atomizing nozzle, said oil being drawn through said nozzle by the syphoning action of said steam, whereby said oil is atomized by passage through said nozzle, means for supplying energy to said heating element contained in said second compartment to heat said water for the production of steam and means for igniting said atomized oil spray produced from said atomizing nozzle.

2. An oil burner as defined in claim 1 further characterized by said float controlled valve in said first cornpartment of said boiler comprising a bell crank, pivot means positioning said bell crank in said first compartment, a valve member aifixed at a first end of said bell crank and operable against a valve seat on said water supply means and a float afiixed at a second end of said bell crank whereby a constant level of Water may be maintained in said boiler.

3. An oil burner as defined in claim 1 further including means for flushing said water contained in said boiler to purge sediment collected therein, said means including a drain pipe positioned in communication with said second compartment, a valve positioned in said drain pipe and means for periodically actuating said valve to discharge a portion of said water contained within said boiler.

4. An oil burner as defined in claim 1 in which said heating element comprises an electrical immersion heating device and in which said means for supplying energy to said device comprises a source of electrical energy.

5. In an oil burner including an atomizing nozzle and a supply of fuel oil, the improvement comprising a steam boiler, a wall within said steam boiler dividing said boiler into first and second compartments, means connecting an external supply of water to said first compartment, float controlled water inlet valve means in said first compartment to control the supply of water to said boiler and to maintain the water in said boiler at a predetermined level, said wall having openings therethrough above and below the surface of the water in said boiler whereby the steam pressure and the water level in said first and second compartments may be equalized, an electrical heating element positioned immediately below the surface of the water in said second compartment to generate relatively dry steam by surface boiling of the water, said wall isolating said float controlled valve from turbulence in said water due to the operation of said heating element, means connecting said supply of fuel oil to said nozzle, means connecting the steam from said boiler to said nozzle whereby said steam and said nozzle provide syphoniug action for said nozzle whereby said fuel oil for periodically flushing a port-ion of said Water to purge said boiler. is drawn to said nozzle and atomized therein, and means 6. In an oil burner, a steam boiler as defined in claim 5 wherein said means for periodically flushing a portion of said water to purge said boiler comprises a drain pipe in communication with said second compartment, a valve normally closing said drain pipe and valve operating means for periodically operating said valve to discharge a portion of said fluid in said boiler.

References Cited by the Examiner UNITED STATES PATENTS 1,932,447 10/1933 Caplan 219-384 1,963,340 6/1934 Thorne et al. 158-75 2,304,468 12/ 1942 Mahler 15875 2,594,063 4/ 1952 Norman 12231 2,729,068 1/ 1956 Mitchell.

FOREIGN PATENTS 459,770 9/ 1949 Canada.

FREDERICK L. MATTESON, JR., Primary Examiner.

MEYER PERLIN, JAMES W. WESTHAVER,

Examiners. 

1. AN OIL BURNER COMPRISING A STEAM BOILER, SAID STEAM BOILER INCLUDING A FIRST COMPARTMENT AND A SECOND COMPARTMENT, MEANS CONNECTING AN EXTERNAL SUPPLY OF WATER TO SAID FIRST COMPARTMENT OF SAID STEAM BOILER, FLOAT CONTROLLED VALVE MEANS POSITIONED WITHIN SAID FIRST COMPARTMENT AND OPERABLE TO MAINTAIN A CONSTANT LEVEL OF WATER IN SAID BOILER, A WALL WITHIN SAID BOILER SEPARATING SAID FIRST AND SAID SECOND COMPARTMENTS SAID WALL EXTENDING LESS THAN THE FULL DISTANCE TO THE TOP OF SAID BOILER AND LESS THAN THE FULL DISTANCE TO THE BOTTOM OF SAID BOILER AND EXTENDING HIGHER THAN SAID CONSTANT WATER LEVEL THEREIN TO PROVIDE PRESSURE EQUALIZATION BETWEEN SAID FIRST AND SAID SECOND COMPARTMENTS AND GRAVITY FLOW OF WATER FROM SAID FIRST COMPARTMENT OF SAID SECOND COMPARTMENT, SAID WALL ISOLATING THE VALVE MEANS FROM THE BOILING ACTION OCCURRING IN THE SECOND COMPARTMENT, A HEATING ELEMENT POSITIONED IN SAID SECOND COMPARTMENT IMMEDIATELY BELOW THE SURFACE OF SAID WATER WHEREBY STEAM IS PRODUCED IN SAID BOILER BY SURFACE BOILING OF THE WATER THEREIN, A STEAM OUTLET FROM SAID BOILER, AN ATOMIZING NOZZLE, MEANS CONNECTING SAID STEAM OUTLET TO SAID ATOMIZING NOZZLE, A SUPPLY OF FUEL OIL, MEANS CONNECTING SAID SUPPLY OF FUEL OIL TO SAID ATOMIZING NOZZLE, SAID OIL BEING DRAWN THROUGH SAID NOZZLE BY THE SYPHONING ACTION OF SAID STEAM, WHEREBY SAID OIL IS ATOMIZED BY PASSAGE THROUGH SAID NOZZLE, MEANS FOR SUPPLYING ENERGY TO SAID HEATING ELEMENT CONTAINED IN SAID SECOND COMPARTMENT TO HEAT SAID WATER FOR THE PRODUCTION OF STEAM AND MEANS FOR IGNITING SAID ATOMIZED OIL SPRAY PRODUCED FROM SAID ATOMIZING NOZZLE. 